Identifying the source of SARS-CoV-2 is important for containing fresh outbreaks
By concluding that a virus leak from a laboratory in China’s Wuhan, where the SARS-CoV-2 virus first emerged, is “extremely unlikely” and did not require further study, a 17-member WHO team and its Chinese counterparts have put to rest conspiracy theories that emerged early during the pandemic. While many scientists had dismissed the lab-origin theory, in mid-February 2020, a group of 27 prominent scientists from outside China “strongly condemned conspiracy theories” in a letter published in
The Lancet. The group said scientists who had analysed virus genome sequence data shared by China and multiple countries could “overwhelmingly conclude” that SARS-CoV-2, like emerging pathogens, had originated in wildlife. Even a year since the letter and after nearly half-a-million genome submissions to a public database, scientists have not found any sign of direct human influence. The WHO team’s investigation now strongly suggests virus origin to a natural reservoir in bats, but unlikely to have been in Wuhan, which is miles from any natural bat habitat. The virus jumping directly from bats to humans is highly unlikely and initial investigation too suggests the role of an intermediary host species. The team has not been able to confirm the intermediary host.